The printing process is one small part of the total quality control procedure for a MICR printing system user. Quality and accuracy of the check documents must be closely controlled during printing to prevent problems from occurring when the document is processed off-site. The MICR line is the line of machine readable information that is printed at the bottom of each check. Financial institutions are dependent on the accuracy and integrity of the data in this line. Unlike the fixed elements of the form, the MICR line must be printed using magnetic ink and a special MICR font, such as E13B or CMC7.
Under current law, a bank may send the original paper check for payment unless it has an electronic payment agreement with the paying bank. Under Check 21 legislation in the United States, by authorizing the use of a new negotiable instrument called a “substitute check” (aka image replacement document), electronic check processing is enabled without mandating that any bank change its current check collection practices. The substitute check is a paper reproduction of an original check that contains an image of the front and back of the original check, which is suitable for automated processing in the same manner as the original check, as long as the check image meets other technical requirements, such as having mandated image quality, otherwise referred to as image readiness that includes acceptable print contrast between the check background and any critical data (e.g. signatures, printed amounts, etc.) placed over the background.
As a result of Check 21, banks that wish to scan the original paper check to create a substitute check require it to satisfy not only MICR character requirements but also print contrast signal (PCS) standards with respect to the check background. Print contrast acceptability is the design attribute of a check that ensures optimum recognition of amounts, legibility of handwriting, MICR character capture optically, and reasonably low file size that are positioned overtop of any background design images on the surface of the check.
When designing MICR documents, it is critical to remember that the document acts as a vehicle to transfer money from one party to another. The MICR document must clearly communicate the information required to complete that transfer, without interference from colorful backgrounds or confusing layout. Digital image capture, processing, and storage for the entire check make this requirement more important. Work is in progress to make the digital image of a check legally binding when captured and processed by banks. This is necessary to permit truncation of the paper documents early in processing and eliminate the cost of transporting the paper to the issuing bank. Checks should be designed to be easily interpreted when digitized into black and white images. MICR documents are not the only documents in which readability is a concern. Many payment processing systems are designed to use an OCR-printed turnaround document to direct a check based payment. In these cases, readability of the OCR line may be compromised if the document is printed using magnetic ink. The processing system detect checks by the presence of magnetic ink and initiate an E13B font recognition routine. If the turnaround document is magnetic, failure to read would result. Therefore, MICR printers are not recommended when an OCR font is used for data collection.
The smoothness of paper used on which to print the MICR characters can impact image quality. With increasing roughness, the print quality of solids and halftones degrades. Extremely rough paper does not properly accept fused dry ink, which rubs or flakes off. Rough papers require a higher density setting and more ink than smooth papers to achieve the desired level of image darkness, because surface irregularities must be filled in with ink. In this case, the amount of magnetic ink used to print the MICR characters can also be irregular.
Further, it is recognised that quality control of the MICR characters, for each MICR symbol, is also impacted by any variability or non-standard numbers or spaces between those symbols, which must be properly registered so that the fields do not flow into one another.
Further, each MICR symbol and character has an ideal waveform and nominal signal strength. Every MICR printing technology modifies the waveform from the ideal in a different way, so that the nominal MICR signal varies somewhat among the characters and symbols. These variations from the norm are characteristics of the printing technology and font design
If a MICR quality issue arises, it can be visible on the printed document. Even signal strength problems can be seen if prints are compared. Low signal characters are thin and poorly formed; high signal characters are fat and usually surrounded by xerographic background. However, occasionally, problems are reported by test equipment, but no problem is visible. This is usually due to improper use of intelligent magnetic test equipment, which evaluates optical specifications using magnetic waveforms. Equipment vendors are aware of the limitations of their products, and therefore recommend visual inspection of suspected characters. Some users, however, misinterpret these findings as specifications failures. It is important to understand the differences between optical and magnetic measurements and why all ANSI standards for MICR character dimensions can be evaluated optically only.
Further, MICR signal strength is measured magnetically, along with uniformity and spots, and is specified numerically as 50 to 200 percent of nominal. Waveform uniformity is not specified numerically, but as an indicator for visual inspection. Spots are categorized as magnetic or non-magnetic, because different size allowances apply. No other specifications are measured magnetically. Any MICR failures other than signal strength must be confirmed optically. However, it is recognized that the magnetic waveform test may pass the magnetic signal strength criteria but are actually contain poorly printed (e.g. too short, too narrow, improper spacing, too light, etc.) characters in those cases where the magnetic ink may be of sufficient metal oxide content/strength to mask those visual deficiencies.
Accordingly, it is recognised in the industry that one must identify the source of the problem for MICR character reading errors before one can implement corrective actions. For document quality problems, one can best identify the cause by examining the rejected document and determining the most likely reason for rejection. However, rejected documents may not be available, or they may not visibly show any printer or application-related issues.